Combine: canned milk, yeast and sugar (Note: Heat milk to no more than 105 degrees otherwise yeast will not activate).
When yeast mixture has doubled in size Add: egg yolks (reserve egg whites for filling), egg, sour cream, salt, butter and sugar Gradually blend in the 6 cups of flour to mixture one at a time. Mix and cover for 30 minutes.
Separate dough into 4 parts. Roll out 1/4" thick. Spread filling over entire surface of dough, roll from smallest end.
Place on an ungreased cookie sheet and let rise for one (1) hour. Poke fork holes on top, 1/2" apart. Brush with beaten egg and water (mixed) and sprinkle with sugar.
Bake at 350 degrees for 35-40 minutes.